#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char* message);

int main(int argc, char* argv[])
{
    int sock;//用于与服务端通信的套接字
    char message[BUF_SIZE];//存储字符串的
    int str_len;
    struct sockaddr_in serv_adr;//服务器端套接字的地址信息结构体

    FILE* readfp, *writefp;

    if(argc != 3)
    {
        printf("Usage  %s : <ip> <port> \n", argv[0]);
        exit(1);
    }

    //socket()创建套接字
    sock = socket(PF_INET, SOCK_STREAM, 0);
    if(sock == -1)
        error_handling("socket() error\n");
    
    //connect()服务器
    memset(&serv_adr, 0, sizeof(serv_adr));
    serv_adr.sin_family = AF_INET;
    serv_adr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_adr.sin_port = htons(atoi(argv[2]));

    if(connect(sock, (struct sockaddr*)&serv_adr, sizeof(serv_adr)) == -1)
        error_handling("connect() error\n");
    else
        puts("Connected...");

    readfp = fdopen(sock, "r");
    writefp = fdopen(sock, "w");
    while(1)
    {
        fputs("Input message(Q to quit): ", stdout);
        fgets(message, BUF_SIZE, stdin);
        if(!strcmp(message, "q\n") || !strcmp(message, "Q\n"))
            break;
        
        fputs(message, writefp);
        fflush(writefp);
        fgets(message, BUF_SIZE, readfp);//fgets会添加\0
        printf("message from server : %s", message);
    }
    fclose(readfp);
    fclose(writefp);
    return 0;
}

void error_handling(char* message)
{
    fputs(message, stderr);
    fputc('\n', stderr);
    exit(-1);
}
